• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.147-152
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• 2010

Poor fruit set during winter period is one of the biggest problem in plastic tunnel watermelon cultivation. Hand pollination is inevitable to maximize fruit set of the winter watermelon. Productivity and viability of pollen grain and organic solvents for pollen storage were investigated. All cultivars produced more than 10 mg/flower except for 'Kumchun' cultivar. Pollen amount per flower were 13.8 mg in 'Bok' and 12.1 mg in 'Speedkul'. Germination rate of pollen grains incubated at $30^{\circ}C$ right after soaking in pentane solvent were 76% in 'Kumchun' as the lowest and 92% in 'Apollokul' as the highest. The pollen of 'Bok' showed the highest germination rate by 75% after a 15-day storage in pentane. All cultivars showed their pollen germination rate below 25% after a 24-day storage. Among the cuitivars, speed of pollen tube growth in vitro were relatively lower in 'Kumchun' and 'Sambokkul' by below $50\;{\mu}m/hr$. Pollen tube of these cultivars tended to burst during its elongation on the medium. Pollen stored 24 hrs in organic solvents showed 45, 39, 34, 23, and 19% of germination in pentane, ethyl ether, n-hexane, ethyl acetate, and acetone, respectively. Compared with light condition, pollen viability was higher in darkness during pollen storage in organic solvents. Pollen grain was susceptible to the organic solvent. The viability of pollen grains seems to be influenced greatly by duration of soaking pollen in organic solvent and the polarity of solvents. Organic solvent damages surface of pollen grain and extent of damage was varied by the solvents.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.354-361
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• 2012

This study was conducted to evaluate on the freezing tolerance of introduced blueberry cultivars in Korea and to investigate availability of portable timber moisture meter for simple and rapid diagnosis of blueberry-shoot damage by freezing during wintering. Frost tolerance of blueberry cultivars showed big difference that rates of blueberry-shoot death were widely distributed from about 0% to 100% after wintering. Optical density in TTC reduction of blueberry twig treated low temperature was low in order of $-40^{\circ}C$ < $-21^{\circ}C$ < $4^{\circ}C$. Hardiness evaluation of visible injury in the cross-sectional surface color did not agree with that of rates of blueberry-shoot death during wintering. Lowest water content of blueberry stem measured by timber moisture tester during wintering was about 15%. During wintering, water contents of blueberry stems were higher at lower part of tree, but were low at end part of stems, and then when the blueberry grew again for spring, the water content gradually increased to 20~40%. Water content of blueberry stem with freezing injury during wintering decreased to under 5% by desiccation. Therefore it is assummed that the moisture content of blueberry stem injured by freezing during wintering was about under 14%, and it is expected that portable timber moisture meter could be available for rapid diagnosis of blueberry freezing injury in field.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.56-59
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• 2007

We bred new mulberry cultivar through local adaptability test, which was registered as a new cultivar for fruit production. Local adaptability test had been carried out at three places(Suwon, Konju and Cheongju) for three years since 2002. This is tetraploidy variety belonging to (Morus Lhou(Ser.) Koidz.) made by colchicine treatment on growing point of winter buds. Daeseongppong was high yielding in productivity by 48% compared to control cultivar "Chungilppong" for two years. Although Daesungppong was a little lower in sugar content of mulberry fruits, it contains more bioactive materials like C3G, rutin and amino acids than Chungilppong. It is adaptable to every where except the places where cold damage and sclerotial disease happen frequently.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.110-117
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• 2015

We bred a mulberry cultivar named Sangmaru, through local adaptability test, which is under registration as a new cultivar for fruit production. Local adaptability test had been carried out at three places (Suwon, Cheongju, and Jangseong) for seven years from 2008. This is tetraploidy variety belonging to Morus alba L. made by colchicine treatment on growing point of 'Chungil (Morus alba L.)' winter buds. Sangmaru was high yielding cultivar in fruit productivity by 6% compared to control cultivar 'Chungil (Morus alba L.)' for five years. Although Sangmaru was similar in sugar content of mulberry fruits, it was bigger than that of 'Chungil'. It is adaptable to every where except the places where cold damage and sclerotic disease happen frequently.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.171-177
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• 2012

We bred a mulberry cultivar named Sangberry, through local adaptability test, which is under registration as a new cultivar for fruit production. Local adaptability test had been carried out at four places(Suwon, Kongju, Jangseong and Sangju) for six years from 2005. This is tetraploidy variety belonging to(Morus alba L.) made by colchicine treatment on growing point of winter buds. Sangberry was high yielding cultivar in fruit productivity by 70% compared to control cultivar "Chungilppong(Morus alba L.)" for four years. Although Sangberry was a little lower in sugar content of mulberry fruits, it contains more bioactive materials like C3G, rutin and amino acids than Chungilppong. It is adaptable to every where except the places where cold damage and sclerotic disease happen frequently.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.659-668
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• 2021

The purpose of this study is to propose a ventilation corridor management plan to improve the thermal environment for Busan Metropolitan City. To this end, the characteristics of hot and cool spots in Busan were identified by conducting spatial statistical analysis, and thermal image data from Landsat-7 satellites and major ventilation corridors were analyzed through WRF meteorological simulation. The results showed the areas requiring thermal environment improvement among hot spot areas were Busanjin-gu, Dongnae-gu, industrial areas in Yeonje-gu and Sasang-gu, and Busan Port piers in large-scale facilities. The main ventilation corridor was identified as Geumjeongsan Mountain-Baekyangsan Mountain-Gudeoksan Mountain Valley. Based on the results, the ventilation corridor management strategy is suggested as follows. Industrial facilities and the Busan Port area are factors that increase the air temperature and worsen the thermal environment of the surrounding area. Therefore, urban and architectural plans are required to reduce the facility's temperature and consider the ventilation corridor. Areas requiring ventilation corridor management were Mandeok-dong and Sajik-dong, and they should be managed to prevent further damage to the forests. Since large-scale, high-rise apartment complexes in areas adjacent to forests interfere with the flow of cold and fresh air generated by forests, the construction of high-rise apartment complexes near Geumjeongsan Mountain with the new redevelopment of Type 3 general residential area should be avoided. It is expected that the results of this study can be used as basic data for urban planning and environmental planning in response to climate change in Busan Metropolitan City.

• Ecology and Resilient Infrastructure
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• v.10 no.1
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• pp.11-19
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• 2023

Alien species are known to threaten regional biodiversity globally, which has increased global interest regarding introduction of alien species. The Ministry of Environment of Korea designated species that have not yet been introduced into the country with potential threat as alert alien species to prevent damage to the ecosystem. In this study, potential habitats of Esox lucius and Maccullochella peelii, which are predatory and designated as alert alien fish, were predicted on a national basis. Habitat suitability was evaluated using EHSM (Ecological Habitat Suitability Model), and water temperature data were input to calculate Physiological Habitat Suitability (PHS). The prediction results have shown that PHS of the two fishes were mainly controlled by heat or cold stress, which resulted in biased habitat distribution. E. lucius was predicted to prefer the basins at high latitudes (Han and Geum River), while M. peelii preferred metropolitan areas. Through these differences, it was expected that the invasion pattern of each alien fish can be different due to thermal preference. Further studies are required to enhance the model's predictive power, and future predictions under climate change scenarios are required to aid establishing sustainable management plans.

• Journal of Korean Society of Rural Planning
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• v.29 no.1
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• pp.69-79
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• 2023

Uiseong-gun, Gyeongsangbuk-do, one of the representative small rain regions, has developed a traditional irrigation farming system while overcoming and adapting to unfavorable agricultural environments from the days of the ancient nation of Jomunguk to the present. In 2018, its value was recognized and designated as Nationally Important Agricultural Heritage System No. 10. This study was conducted with the purpose of examining the characteristics of the traditional irrigation farming system in Uiseong from the viewpoints of irrigation facilities, irrigation communities, and agricultural activities. The research results are as follows. Uiseong-gun has been expanding irrigation facilities for agriculture since long ago, and it has been investigated that a total of 6,227 irrigation facilities are currently distributed along the Wicheon water system that crosses Uiseong-gun from east to west. Irrigation facilities appear differently depending on the topography. The irrigation facility has a 'su-tong' as an irrigation passage and a corkscrew structure 'mot-tchong' as a water quantity control device, so the amount of water was adjusted as needed. Through this facility, surface water with warmer temperature is supplied to the farmland to prevent cold damage to crops. Uiseong has developed activities to organize irrigation communities in one village or several villages to secure agricultural water from an early age. Currently, this tradition continues, and a total of 213 irrigation communities manage 375 irrigation facilities (6.0% of all irrigation facilities). Through this organization, called Mong-ri-gye, water for agriculture is obtained, managed, and distributed equitably. In order to increase agricultural production, Uiseong implemented double cropping by converting rice fields and fields. In the case of Mt. Geumseong, double cropping of rice and barley was mainly carried out until the 1970s, but since the 1980s, double cropping of rice and garlic has been implemented with higher income. One of the unique features of the agricultural system of this region is the spectacular landscape that changes simultaneously from field to rice field in spring and from rice field to field in autumn.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.320-327
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• 2021

Freezing damage to fruit trees is frequently occurring due to cold in winter and low temperature in spring to abnormal weather caused by global warming. In particular, the freezing injury of deciduous fruit trees is highly dependent on the developmental stages of the flower buds. And the cold resistance is weakened as the growth progresses, so it is most vulnerable period from flowering to petal fall(post-bloom). Therefore, this study was conducted to analyze the cause of the freezing injury caused by severe low temperature to 'Fuji', which has a late flowering period more than 'Hongro' in April 2020. We investigated freezing injury rate in 'Fuji' and 'Hongro' apple trees damaged by natural low temperature at Boeun-gun, Chungbuk province in Korea. In addition, flower buds in the same developmental stage (tight cluster) were treated artificially low temperature to investigate the injury rate for accurate comparative analysis between varieties, and to analyze the soluble sugar and hormone contents in the flower buds. As a result of survey in natural low temperature, 'Fuji' had a higher injury rate than 'Hongro' in both orchards, and in particular, B orchard 'Fuji' had the highest injury rate of 60.5%. Also there were significantly difference in the freezing injury rate between 'Fuji' and 'Hongro' in artificially low temperature treatments. As a result of analyzing the soluble sugar contents in 'Hongro' was higher than 'Fuji'. Also ABA, IAA and SA contents were more increased in the damaged tissue than in the normal flower buds by low temperature treatments. Consequently, it was assumed that the freezing injury was closely related to soluble sugar contents in the flower buds. In particular, the freezing injury rate was negatively correlated with the sorbitol contents.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.64-70
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• 2013

The greenhouse whitefly, Trialeurodes vaporariorum, is an economically important pest for greenhouse crops because they cause direct damage by feeding on plant nutrients and indirect damage as transmits many virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among greenhouse whitefly population. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of nymph greenhouse whitefly were investigated. Isolated fungus was identified as Isaria fumosorosea by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin, and EF1-${\alpha}$ regions. This fungus was named as I. fumosorosea SDTv and tested for the virulence against nymphs T. vaporariorum and the cold activity, the thermotolerance and the stability of UV-B irradiation on conidia. Mortality rate of greenhouse whitefly showed from 84 to 100% and the virulence increased with increasing conidial concentrations, $1{\times}10^5$ to $10^8$ conidia/ml. Conidia were stable at $35^{\circ}C$, 0.1 $J/cm^2$ of UV irradiation and germinated after 8 days at $4^{\circ}C$. Additionally, the activities of chitinases and proteases produced by I. fumosorosea SDTv were varied according to the medium. In conclusion, I. fumosorosea SDTv which showed high mortality rate against greenhouse whitefly will be used effectively in the integrated pest management programs against the greenhouse whitefly.